Optical system for capsule inspection

ABSTRACT

Medicinal-capsule inspection apparatus. Successive capsules spun on their axis in an inspection position are illuminated by intense light originating at a single lamp filament and reflected onto the capsule from a mirror in the form of a narrow band cut from an ellipsoid and positioned so that the filament is adjacent to one focus and the capsule adjacent to the other focus. The mirror wraps around the capsule endwise and produces on the capsule, as seen by a side-viewing lens and two end-viewing lenses, a narrow well-defined and continuous glare line area which is unique in that it curves over the ends substantially to the axis. The lenses project images of the capsule in side and end elevation. Masks at the image planes block the glare light from acceptable capsules, but contain apertures in selected relation to the image glare light areas, which pass light specularly reflected from defects in selected observation areas on the spinning capsules. Such light acts on light sensors behind the apertures to generate electrical control signals which provide inspection output information.

Vandenberg et al.

Jan. 9, 1973 154] OPTICAL SYSTEM FOR CAPSULE INSPECTION [75] Inventors:Willard J. Vandenberg; H1 Chul Chae, both of Indianapolis; Elmer R.Stewart, Camby; Wayne R. Palmer, Mooresville, all of Ind.; Howard R.Padgitt, Park Ridge, 111.

[73] Assignee: Eli Lilly and Company, Indianapolis,

Ind.

[22] Filed: Sept. 23, 1971 [21] App1.No 183,199

[52] US. Cl.. ..356/l98, 209/111.7, 250/224, 350/293, 356/209, 356/237[5 I] Int. Cl. ..G01n 21/22, G01n 21/48 [58] Field of Search..209/111.5,111.6,111.7; 250/224; 356/198, 209, 237; 350/293 56]References Cited UNITED STATES PATENTS 3,123,217 3/1964 McMillan et al...209/1 1 1.5

Primary Examiner-Ronald L. Wibert Assistant Examiner-F. L. EvansAttorney-Verne A. Trask et al.

[57] ABSTRACT Medicinal-capsule inspection apparatus. Successivecapsules spun on their axis in an inspection position are illuminated byintense light originating at a single lamp filament and reflected ontothe capsule from a mirror in the form of a narrow band cut from anellipsoid and positioned so that the filament is adjacent to one focusand the capsule adjacent to the other focus. The mirror wraps around thecapsule endwise and produces on the capsule, as seen by a side-viewinglens and two end-viewing lenses, a narrow welldefined and continuousglare line area which is unique in that it curves over the endssubstantially to the axis. The lenses project images of the capsule inside and end elevation. Masks at the image planes block the glare lightfrom acceptable capsules, but contain apertures in selected relation tothe image glare light areas, which pass light specularly reflected fromdefects in selected observation areas on the spinning capsules. Suchlight acts on light sensors behind the apertures to generate electricalcontrol signals which provide inspection output information.

51 Claims, 20 Drawing Figures PATENTED JAN 9 I975 SHEEI 1 BF 6PAIENTEflJAu Basra 3.709.598

sum s or 6 PATENTEDJAN 9191a SHEEI 8 [1F 6 OPTICAL SYSTEM FOR CAPSULEINSPECTION CROSS REFERENCES The optical system of this application isespecially useful in the inspection apparatus disclosed in the copendingapplication of William D. Wagers, Jr., et al., Ser. No. 105,262, filedJan. ll, I971. The ellipsoidal mirror lighting system disclosed isclaimed in a copending application of Howard R. Padgitt, Ser. No.223,199 filed Feb. 3, 1972. The output signals may be processed asdisclosed in copending application of Hi Chul Chae et al., applicationSer. No. 183,948 filed Sept. 27, l 97 l BACKGROUND OF THE INVENTION Thisinvention relates to an optical system for rapidly inspecting largenumbers of medicinal capsules positioned successively in an inspectionposition where each capsule is spun on its axis to expose its entiresurface for inspection.

Medicinal capsules are made in large numbers on complex and sensitivemachines, from gelatin or other material. Gelatin capsules consist ofcaps and bodies which are formed by dipping pins in a gelatin solution,causing the coatings on the pins to set, stripping the set coatings,cutting them to length, and telescopically assembling the empty caps andbodies with sufficient tightness to stay together during handling asempty capsules but sufficiently loose to permit disassembly for filling.The empty capsules must be as free as possible of imperfections, notonly as a matter of product quality, but especially to provide properoperation of the machines in which they are filled, to avoid waste andimproper dosage of the medicinal material, and to avoid production ofimperfect filled capsules.

The requisite capsule quality requires I percent inspection of emptycapsules before their use or sale to others for use. Heretofore, thishas been done by visual observation by inspectors as the capsules areconveyed in a single-thickness layer across an illuminated screen. Suchvisual inspection is expensive, and not fully effectrve.

Representative capsules consist of caps and bodies each having a deepcupshape with a generally cylindrical side wall and a rounded end. Thetelescopically assembled capsule may vary considerably in length. Theskirt of its cap is commonly formed with an outward flare or taper. Theexternal surfaces may be out of round either because of variation inwall thickness or because of distortion. Several other permissiblevariations may occur in acceptable capsules. Thus, even good capsulespresent a somewhat irregular shape which renders inspection a difficultproblem.

Effective inspection is also made difficult by the large number andvariety of defects which can occur. Defects which should be found oninspection include split or cracked capsules, capsules with holes ornotches in their wall, mashed or flattened capsules, telescopicallydeformed capsules, cuttings encircling or otherwise attached to thecapsules, incomplete capsules, crimps, turned edges on the caps, blackspecks, dents, bubbles, depressed ends, ragged edges on the cap,scrapes, pin marks, thin spots, etc. These different defects responddifferently to optical inspection, and some require different inspectionconditions than others. Also, inspection apparatus should be able todetect defects in colorless and transparent capsules as well as incapsules of various colors and degrees of translucency and in two-colorcapsules, that is with caps and bodies of different colors. inspectionshould also apply to capsules of different shapes, including those withhemispherical ends and those of parabolic shape.

It has been found especially difficult to inspect for defects in therounded shoulder areas at the ends of the capsules, between thegenerally straight edges and the rounded ends, and especially in theparabolic surfaces of capsules having parabolic body ends.

Inspection must also take account of deviations built into the capsulesfor special purposes. In some capsules, a pair of diametrically oppositeinternal bosses are formed in the cap to bind the caps and bodies ofempty capsules against separation. Also, some capsules have a pluralityof circumferentially-spaced internal lands in the caps to retaintogether the caps and bodies of assembled filled capsules, such asdisclosed in Hostetler et al., US. Pat. No. 3,173,840 of Mar. 16, 1965,entitled Separation-Resistant Capsules. Such internal bosses and landsproduce external surface deviations similar to some defects.

Automatic or machine inspection has not previously been accomplished. lna previous study for the assignee of this application, some 10 yearsago, Stanford Research institute the final report of Stanford ResearchInstitute is of record in the cited copending application of Wagers etal., Ser. No. 105,262 proposed an inspec tion system in which capsuleswere rotated rapidly in front of a moving set of small photosensitivescanning apertures, and built a hand-fed laboratory scanning machine forstudying this proposal. While the optical system of that study appearedpromising, no means was available to handle and present capsules for theinspection at a sufficiently high rate, and when such a means had beendeveloped as disclosed in the aforesaid copending application of WilliamD. Wagers, J r., et al., it was then found that the proposed opticalsystem was inadequate, and much development work has been necessary toproduce the present operatively-useful system.

The present invention provides an effective optical system forinspecting capsules presented in succession in a uniform position andorientation and rapidly spun on their axis to present their entiresurface for such optical inspection. it provides for inspecting not onlythe generally cylindrical side surfaces of capsules, but also therounded ends and the shoulder portions between the sides and ends, sothat a complete inspection may be accomplished in a single inspectioncycle at the same inspection station.

The invention is applicable to transparent or colorless capsules as wellas to capsules of uniform color and to two-color capsules. [t is alsoapplicable to capsules having normal surface deviations resulting frominternal bosses and lands, and to capsules of different sizes andshapes, including both those with generally spherical ends, and those inwhich the body end has a parabolic or bullet shaped configuration.

It is convenient to discuss inspection lighting and viewing withreference to specular reflection or glare lines on the surfaces of goodcapsules; yet it is to be remembered that the inspection is not so muchto observe conditions on good capsules but rather to see defects forwhich the capsules should be rejected. In inspection of true surfaces ofrevolution such as those of bearing rollers, it has been proposed, as inStevens US. Pat. No. 2,944,667, to observe light which was specularlyreflected from glare lines, and to sense light decreases in suchobserved specular reflection. This is not effective for capsuleinspection, in part because permissible irregularities of capsule shapemake the glare unstable, and also because of the variety and obscurityof the defects which must be found.

SUMMARY OF THE INVENTION In accordance with the invention, eachsuccessive capsule is rapidly spun on its axis at a predeterminedinspection position in a groove between a pair of spinning drive rollswhile held in the groove by air flow to a suction passage at the bottomof the groove. Such rotation in itself performs an inspection function,in that excessively deformed or incomplete capsules are thrown off therolls and effectively rejected. Each capsule, during its rotation on itsaxis in the inspection position undergoes optical inspection both of itsside area and of its end and shoulder areas. Preferably, the side andend inspections are performed simultaneously, and use a common lightingsystem, but it is contemplated that side and end inspection could bedone separately or with separate lighting means.

The capsule presents a convex reflective surface which forms part of theoptical system, and the lighting system produces specular reflectionfrom that surface into the viewing lens systems over glare line areaswhich can vary in shape and definition depending both on the shape ofthe capsule and on the shape of the light beam with which it isilluminated.

in general, a preferred inspection apparatus includes (1) viewingapparatus which may comprise a side-inspection lens system and two endinspection lens systems; (2) a lighting system which casts light ontothe capsule from a series of points in an elongated narrow area whichwraps around" the capsule lengthwise and, as seen by the lens systems,produces specular reflection over a glare line which is substantiallycontinuous from end to end along the capsule and over its rounded ends;(3) image planes to which the lens system project images of the side andends of the capsule, and (4) light sensors which sense light in suchimages over linear areas spaced from the glare lines therein. Theinspection cycle for each spinning capsule is continued through aplurality of capsule revolutions, for example five revolutions, toprovide redundancy in the inspection.

The side-inspection lens system sees the glare line over the entirelength of the generally cylindrical side surface and may to some extentsee the glare line on the adjoining shoulder surfaces of the capsule.Side inspection preferably utilizes a series of light sensors responsiveto light in different portions of a substantially continuous linear areaparallel with and spaced from the glare line the side image of thecapsule, and one or more of these sensors may sense built-in deviationsas from separation-resisting internal lands and bosses in the capsulewall.

inspection of end and shoulder areas of the capsule is greatlyfacilitated by the "wrap-around" lighting system, which produces anelongated glare line over substantially the whole lengthwise curvedsurface of the capsule end, as seen by a single lens system locatedbeyond the capsule end. Without such warp-around lighting only a smallspot of glare appears. The wraparound lighting and linear glare linepermits the viewing system to see defects in all parts of the difficultend and shoulder areas.

With an end-viewing lens system which sees the capsule end-on, theelongated glare line appears as a radial line on the image of thecapsule end. The end inspection may utilize only a single light sensorarranged to sense light in radial linear areas of the end-image, spacedangularly from the radial position of the glare line.

With the side and end sensors arranged to sense light in image areasspaced from the glare areas, they are responsive to both decreases andincreases in light. They will thus see decreases in difi'use light fromtheir inspection areas such as may be caused by black spots, holes,cuts, and the like in such inspection areas. Also, and especially, theywill see increases in light caused by specular reflection into thesensors from defects such as bubbles, crirnps, and the like whichproduce abrupt changes in the curvature of the capsule surface.

The sensors are connected to electrical circuits in which they producesignals which contain variations or spikes corresponding to lightvariations representing the observed capsule defects. These signals areprocessed and analyzed, as to control the operation of accept-rejectmechanism to accept or reject the inspected capsules and to count boththe accepted and rejected capsules.

In signals from light sensors arranged to observe defects in areas ofthe capsule which contain no built-in deviations, the occurrence of asingle spike of prede termined size on each revolution of the capsulemay be taken as sufiicient to cause rejection of the capsule. Where thelight sensor is one which sees built-in deviations the signal processingand analysis must take account of the appearance in the signal of thevariations corresponding to such built-in deviations. A preferred methodof processing signals containing such built-in spikes is to measure thetime interval between spikes so that the presence of a defect-causedspike will produce a time measurement between successive spikes which isshorter than the predetermined normal time between spikes from built-indeviations. A reject signal can then be derived from the abnormal shorttime measurement.

The substantially continuous end-to-end glare line on the capsule isproduced by specular reflection of light rays suitably directed onto thesurface of the spinning capsule from a plurality of points over anelongated narrow light source area.

The narrowness is desirable to delineate a narrow glare line area on thecapsule and in its image, so that a predetermined and uniformrelationship is obtained between the glare line area and the lightsensing area. The elongation of the light source area is desirable toproduce uniform end-to-end illumination of the capsule. The light sourcearea should extend over a wide angle in the capsule plane so that thelight rays converge on to the capsule over that wide angle to produce asubstantially continuous end-to-end glare line.

Operative illumination may be obtained in various ways. For example, anelongated narrow light source area may be provided by the use of one ormore lamps having elongated line filaments, by shaped luminescent tubes,by means of light conducting fiber optics, beamsplitting opticaldevices, etc. We have found, however, that best results are obtained bythe use of a single light source and a shaped mirror in the form of anarrow segment of an ellipsoidal surface, with the mirror disposed insuch a way that the light source is adjacent to one focus of theellipsoidal mirror surface and the capsule is adjacent to the otherfocus of that ellipsoidal surface, as shown in the aforesaid copendingapplication of Howard R. Padgitt. That illumination system produces athin wedge-shaped beam of converging light rays directed toward thecapsule from over a wide angle and which wraps around the ends of thecapsule to produce specular reflection over a narrow glare line which iscontinuous end-to-end along the surface of the spinning capsule.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustratethe invention, and show a preferred specific embodiment of theinvention. In such drawings:

FIG. 1 is a sectional view showing in side elevation mechanism forsupplying capsules in sequence at high feed rates to an indexinginspection head;

FIG. 2 is a plan view, with parts broken away, of the inspection head,with an optical inspection system in accordance with the invention showndiagrammatically;

FIG. 3 is a vertical section on the line 3-3 of FIG. 2;

FIG. 4 is a side elevation, on an enlarged scale, one of the drive rollsof the inspection head, in relation to to a representative capsule;

FIG. 5 is a plan view of optical inspection mechanism embodying theinvention, shown in relation to the inspection position on theinspection head;

FIG. 6 is an end elevation of the optical mechanism shown in FIG. 5;

FIG. 7 is a side elevation of the optical mechanism shown in FIGS. 5 and6;

FIG. 8 is a side elevation, with the cover plate removed, of a preferredillumination system, showing diagrammatically the positions of the lightsource and capsule in relation to the foci of the ellipsodial mirror;

FIG. 9 is a front elevation of the illumination mechanism shown in FIG.8, with the front window removed and with parts shown in section;

FIG. 10 is a side elevation of the illuminated capsule as seen from thepoint of view of the side scanning lens system;

FIG. 11 is an end elevation of the illuminated capsule as seen from thepoint of view of the top scanning lens system;

FIG. 12 is a side elevation like that of FIGv 11 showing an illuminatedcapsule of the type having a parabolic end, sometimes referred to as aparacap" capsule;

FIG. 13 is a diagram of the side-inspection optical system, takensubstantially as a horizontal section on the line l313 of FIG. 8;

FIGS. 14a and 14b are enlarged portions of the optical system of FIG.13;

FIG. 15 is a view of the image of a capsule as it appears at the imageplane of the side-viewing optical system, showing the relationship ofthe glare line and the mask openings;

FIG. 16 is a diagrammatic vertical section showing the relationship ofthe image-plane mask and four photo detector devices used to inspectfour areas of the capsule as seen in FIG. 15;

FIG. 17 is a diagram of the end-inspection optical system takensubstantially as a vertical section in the plane of FIG. 8;

FIG. 18 is an enlarged portion of the diagram of FIG. 17; and

FIG. 19 is a view showing the image of the capsule end as seen in theimage plane of FIG. 17 and showing the relationship of the glare line toa preferred form of mask opening.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A representativecapsule 25, as shown in FIGS. 4 and 10, comprises a body 50 having agenerally cylindrical or slightly flaring side wall 49 and ahemispherical end 51. A cap 52 is telescopically received over the openend of the body 50 and includes a hemispherical end 53 and a side wallor skirt portion 55 which is generally cylindrical but commonly flaresoutward toward its open end. The cap is formed with two diametricallyopposite internal bosses 54 for gripping the body 50 to resist cap andbody separation and these appear as slight depressions in the outersurface of the cap. The cap is also formed with three broad internallands 56 at the shoulder portion where the end 53 joins the side 55, andthese produce three sets of depressions and ribs on the surface of thecap shoulder. The deviations thus occurring on the surface of thecapsule, which is otherwise designed as a surface of revolution, aretaken into account in processing and analyzing the inspection results.

The capsule handling and feeding mechanism shown in FIG. 1 comprises ahopper 10 for reception of bulk capsules, having a reciprocatingagitating bar 12 at its bottom adapted to feed capsules from the hopper10 to a bottom trough and there to the upper stretch of a chain conveyor14 trained about a lower sprocket I6 and an upper sprocket or transferwheel 18. As the conveyor leaves the hopper 10 it passes through arectifying station comprising a brush 20 and a belt 22 operative inconjunction with the shape of the buckets 15 of the conveyor to reversethe position of body-forward capsules so that all of the capsules in theconveyor are uniformly presented in a cap-forward position. The capsulesthen pass over the upper sprocket or transfer wheel 18 where internalplungers I9 lift the capsules from the'conveyor buckets and transferthem successively to the indexing inspection head 24.

The inspection head 24, FIGS. 2 and 3, comprises a circumferentialseries of spaced vertical rollers 26, forming between them acircumferential series of capsule receiving grooves 28. The bottom ofeach groove is open to a suction passage 30 for communication withcontrol chambers and passages within the head. Suction applied throughsuch passages 30 retains the capsules 25 in the grooves, and release ofthe suction and/or an air blast discharges the capsules off the head.

The inspection head 24 rotates clockwise as seen in FIG. 2 and carriescapsules from a LOAD station at the bottom through three indexing stepsto an INSPECT station at the right and then through three additionalindexing steps to a REJECT station at the top and an ACCEPT station justbeyond the reject station.

The indexing drive to the inspection head 24, is through a central shaft32 shown in FIG. 3. This drives a hub 34 on which a ball bearing 36supports a ring gear 38 which is continuously driven by a spinner drivegear 40 and which drives pinion gears 42 fixed on the shafts 43 of thecapsule drive rollers 26. This drive train causes the rollers 26 to spinthe capsules 25 in the grooves 28 during each indexed stop position ofthe inspection head. The ring gear 38 is desirably driven continuouslyin the same direction as the indexing hub 34, which produces the desiredspinning rotation of the drive rolls 26 and capsules 25 during indexedstops and temporarily reduces such rotation during indexing movements.

The capsule driving rollers 26 are desirably shaped as shown in FIG. 4,with an upper cylindrical half 44, a lower frusto-conical half 46, and asharply defined shoulder 48 between the two. The capsule is in capdownposition, so that its cylindrical body side wall 49 bears against thecylindrical upper half 44 of the roll 26 and the upper end edge of thecap 52 abuts against the shoulder 48 of the roller 26. The lower conicalsurface 46 of the roll 26 stands clear of the flared side wall 55 of thecapsule cap 52 but engages the capsule cap 52in a substantially circularportion between the indentations 54 and 56. Each pair of rollers 26 thussupports a capsule 25 for substantially stable rotation on its axis, anddrive the capsule in that rotation.

For applying suction or air flow control of the capsules, the upperportion of the inspection head 24 is formed of a ring 58 defining acylindrical cavity in which is seated a valve block 60 held in fixedposition within the ring 58 by a manifold 62. As seen in FIG. 2, thevalve block 60 has a main suction chamber 64 which applies suction tothe suction passages 30 throughout the travel of the capsule grooves 28from the loading station to, but short of, the reject station. Oppositethe REJECT station, the valve block has a suction chamber 66 which isnormally connected to a suction supply line 63 through a valve 65 butwhich is switched to an air pressure supply 67 through a valve 69 whenthe capsule in that position is to be rejected, so that instead of thecapsule being held in the groove 28 by suction, it will be ejected by anair blast through the passage 30. The valves 65 and 69 can be shiftedsimultaneously by solenoids. Opposite the ACCEPT station, the valveblock 60 has an air pressure port 68 which is continuously connected tothe air pressure supply 67 to feed air under pressure to the passage 30at this index position and thereby eject from the inspection head allcapsules which are not ejected at the reject position. With thisarrangement, control of the valves 65 and 69 determines whether suctionor air is applied to the control chamber 66 and this determines whethereach capsule which reaches the reject station will be rejected orretained for discharge at the accept station. Such control may beeffected in response to the inspection output signal from the inspectionwhich occurs at the inspection station.

The inspection which occurs at the INSPECT station is indicateddiagrammatically in FIG. 2 and is more fully described below. Thecapsule at this position is illuminated from a high intensity lamp 70 byway of a mirror 72 in the form of a narrow band cut from an ellipsoidalsurface. As shown in FIG. 8, the mirror band extends in the plane 74 ofthe capsule axis through an arc of approximately 160 about the center ofthe capsule so that it extends substantially to the capsule axis itself.This projects onto the capsule a circumferentially-narrow,longitudinally-wide beam or wedge of light rays which approach thecapsule from points distributed over a wide angle in the plane of itsaxis. This produces specular reflection into the lens of theside-viewing lens system on the axis 78, and causes that specularreflection to occur from a narrow and welldefined glare area along theentire side of the capsule. The side-viewing lens 80 projects an imageof the capsule at an image plane 82. Here, the light from the glare lineis blocked by a mask 84 containing an aperture 86 close beside the imageof the glare line. Light sensing means, shown as a photo detector device88, is positioned behind the aperture, and this is preferably set torespond both to decreases in the observed light and especially also tolight increases caused by specularly reflected rays directed through theaperture by capsule defects.

The optical mechanism is more fully shown in FIGS. 5, 6, and 7. Itcomprises a mounting table 90 adjustably carrying a base 92 having fixedthereto a lens supporting column 94 in which are adjustably mounted anupper lens tube 96 for viewing the top of the capsule, a lower lens tube98 for viewing the bottom of the capsule and a middle lens tube 100 forviewing the side of the capsule. The column 94 also supports a mirrormount 102 carrying a mirror 104 in position to fold light rays from thetop of the capsule 25 to a horizontal position into the lens tube 96.Similarly, the column 94 supports a mirror mounting 106 having a mirror108 for folding the light rays from the bottom of the capsule to ahorizontal direction into the lower lens tub 98.

The lens tubes carry viewing lens assemblies 109, 1 l0, and 1 1 1 and atthe rear carry adjustment supports 112 for supporting mask carriers 116at the image planes of the lens assemblies. Each adjustment support 112comprises a guide way 114 adapted to receive a mask carrier 116 slidablelaterally in the guide way 114. The upper and lower carriers 116 areadjusted in their support by adjustment screws 118 mounted in sideplates 120. For convenience in resetting the sideviewing optical systemto a predetermined adjustment, the mask carrier 116 (not shown) on themiddle lens tube 100 is engaged at one side by an adjustable springplunger 119 and at the opposite side by a micrometer adjustment screw122.

Each lens tube is adjustable axially of itself, to focus on the capsule,by an adjustment screw 124 which rotates in a fixed position in thecolumn 94 and drives a runner 126 fixed to the lens tube.

Each mask carrier 116 comprises a body and a cover plate 117. The bodyforms a seat for removably mounting a rectangular mask in the imageplane of the lens system, and provides for mounting one or more photodetector devices immediately behind the mask in position to react tolight passing through the aperture areas of the mask. Preferably, singlephoto detectors are used in the top and bottom carriers for inspectingthe capsule-ends, and a plurality of photo detectors are used in thecarrier on the middle lens tube 100, for inspectin g differentlongitudinal areas of the capsule side. The carrier 116 may also containelectronic components used with the photo detector, used as apreamplifier.

For aligning and focusing the system and the mask, the cover plate 117of a mask carrier 116 may be removed and replaced with a frame 129holding a ground-glass image screen at the image plane, either with orwithout the mask being present. In FIG. 6, the capsule-side lens tube100 is shown as provided with such a frame 129 and an image screen 128.An image 25' of the capsule 25 and its glare line is shown on thatscreen 128.

In the arrangement shown in FIGS. -7, the optical systems for viewingthe side and the ends of the capsule have their centerlines in the sameplane, and such plane passes through or lies closely parallel to thevertical axis on which the capsule 25 is rotated at the inspectionposition on the inspection head 24. However, the side and end viewingsystems may be in different planes.

The illumination system shown in FIGS. 5-9 comprises a mounting block130 mounted on the base 92 and supporting a mounting post 132 on which aclamp 134 supports a mirror block 136. The outer side wall of the mirrorblock 136 carries a lamp housing 138 in which the lamp 70 is mounted ina pre-focusing base.

As shown in FIGS. 8-9, the mirror block 136 is machined and polished toform the mirror surface 72 in the form of a narrow strip or bandextending through a very wide angle in the plane of the capsule axis.The mirror shown extends over an angle of approximately I60". The mirrorshould be shaped to reflect light from the lamp 70 onto the capsule overthe whole end-toend surface of the capsule and to direct the light inrays which converge toward the capsule in the plane of the capsule sothat the capsule receives light from a multiplicity of points in anarrow elongated area extending over a wide arc about the capsule.Desirably the mirror surface is also shaped with a transversely concavesurface to concentrate light from its entire width onto the capsule.Further, for uniformity of illumination the length of the light pathsfrom the lamp 70 to the mirror and thence to the capsule should beapproximately uniform in all parts of the system.

One geometric surface which satisfies these requirements to a highdegree is an ellipsoidal surface. The mirror surface 72 shown is thus anarrow band of the surface of an ellipsoid having its two foci F-] andF2 substantially in the positions shown in FIGS. 8 and 13. The centralplane 74 of the mirror section is not on the axis of revolution RR ofthe ellipsoid, but is at an angle thereto as shown in FIG. 13. The twofoci F-! and F-2 are, of course, on the axis of revolution R-R. Thecharacteristic of the ellipsoidal mirror surface 72 is such that lightemanating from the focus F-l is reflected from any and all points of themirror surface 72 to the opposite focus F-2. The lamp 70 has a coilfilament 142 which is desirably located substantially on the axis ofrevolution R-R, close to the focus F-l, and the mirror block 136 is somounted that the capsule 25 lies close to the secondary focus F-2.Preferably, and as shown, both the lamp filament I42 and the capsule 25are slightly defocused and located to the right of the foci. Thisarrangement places the capsule in the light rays converging toward thefocus F-2. From the point of view of the capsule, each point on thesurface of the narrow band of ellipsoidal mirror takes on substantiallythe full brightness of the filament 142. From the point of view of thecapsule, the mirror is the source of light and that source is in theform of an elongated narrow area from all points of which rays of lightare directed toward and converge onto the capsule 25. The area source oflight is narrow circumferentially of the capsule, but extends in a wideangle of nearly 180 in the plane of the capsule 25.

Direct illumination from the lamp to the capsule is desirably avoided.The front of the mirror block 136, to the left in FIGS. 8 and 13 isclosed by a window 146 which desirably has a concave shape as shown inFIG. 8. Such window 146 is fully open to pass all light from the mirrorsurface 72 to the capsule 25, but its front face is blackened over anedge portion to form a mask 148 to block direct illumination of thecapsule from the lamp 70.

The capsule surface is itself a smooth convex reflective surface, atleast approximating a surface of revolution. Light from the mirror 72will be specularly reflected by that capsule surface into the sideandendviewing lenses from a lengthwise glare area on the capsule surfaceand will appear as an intense glare line. The narrow uniform width ofthe mirror will aid in causing the glare line to be uniform in width andsharply defined at its edges. The elongated arcuate shape of the mirrorwill cause the glare line to be substantially continuous from end to endalong the surface of the capsule and to wrap around the curved shoulderand end portions; and this is of special importance for inspecting thoseportions.

FIG. 10 shows a capsule 25 as seen from the point of view of theside-scanning lens 110, when illuminated by the illumination system ofFIGS. 8-9. This illumination produces on the capsule 25 a well definednarrow glare line 150 which extends axially along the surface of boththe body 50 and the cap 52, with the portion on the cap 52 slightlyoffset from that on the body 50 because of the larger diameter of thecap 52. While a glare line on a cylindrical surface would normally berelatively narrow, the glare line 150 on the capsule is well defined andespecially narrow by reason of the narrowness of the mirror 72 fromwhich it is illuminated. In effect, the narrow glare line is an image onthe convex reflective surface of the capsule of the narrow surface ofthe elliptical mirror 72.

The ends 152 of the glare line 150 extend beyond the cylindricalportions 49 and 55 of the capsule 25 and up into the hemispherical endportions 51 and 53 of the body and cap. This is the result of the wraparound characteristics of the ellipsoidal mirror 72, in that that mirrorextends in a wide angle of approximately l60 about the center of thecapsule in the plane of the capsule. As shown in FIG. 8, a bundle ofrays 0 from the filament 142 which strikes the mirror 72 at a pointclose to its centerline Y will be reflected as reflected rays a'onto theside of the capsule 25, and this will produce specular reflectionhorizontally into the entrance pupil of the side-viewing lens 110. Also,a bundle of rays 1) from the filament 142 which is reflected from apoint on the mirror spaced upward from the horizontal axis Y will bereflected as a bundle of rays b which will strike the upper end of thecapsule from an upward inclination, and such rays will cause specularreflection from the hemispherical end surface of the capsule in agenerally horizontal direction into the same entrance pupil of theside-viewing lens 110. It is thus because of this wrap around lightsource arrangement that the glare line 150 on the capsule shown in P10.is caused to extend the full length of the cylindrical side surface andthere-beyond into the hemispherical end surface. That same wrap aroundfeature produces an elongated glare line on the end of the capsule asseen by the end-viewing lens 109 or 111, as shown in FIG. 11, and thiswill be discussed in more detail later.

Inspection of the side area of the capsule is carried out as showndiagrammatically in FlGS. 13 and 14a, b. As has been described, thefilament 142 of the lamp 70 supplies light to the narrow band ofellipsoidal mirror 72, and from the point of view of the capsule 25 highintensity light is reflected from the full width of that band of mirrorsurface 72 in converging rays 156 toward the capsule 25. Theside-viewing lens 110 projects an image 125 of the capsule 25 on theface of the mask 160. A thin wedge-shaped pencil of converging rays 156are specularly reflected from the glare line area 150 on the capsule, asdiverging rays 156', into the entrance pupil of the side-viewing lens110, and such lens produces an image of the glare line area at an area150' in the image plane on the face of the mask 160. The lens 110 showndiagrammatically in FIG. 13 is in practice a lens system, preferably oneof high quality specifically designed for l:l magnification in thisapplication. The plane in which it is focused can have a significantbearing on the results. For example, because of the divergence of thelight rays 156' reflected from the convex specularly-reflecting surfacearea 150 of the capsule, the glare appears to come from a line source151 inside the capsule where the divergent rays 156' intersect. The lens110 should not be focused on that glare line source 151 but insteadshould be focused on the glare surface 150 of the capsule.

At the image plane, all the light rays 156' from the glare line area 150which enter the lens 110 are directed to the glare line image area 150'on the mask, and since this portion of the mask is opaque, all suchglare light is blocked. Close beside the glare line the mask contains anaperture 162, behind which a series of photo detectors l65a-d arelocated to sense light transmitted through the aperture 162. Specularlyreflected light from the vicinity of the observed face of the spinningcapsule normally does not enter the lens 110 and reach the mask aperture162, provided the capsule has no defects. However, when a surfaceirregularity such as a bubble 164 rotates through the vicinity of theglare line area 150, as shown in FIG. 14, a different condition willexist. The surface irregularity or bulge at the bubble 164 may causesome variation in the specular reflection of light from the glare linearea 150, but any such variation at the glare-line image 150' on themask 160 has no effect in the inspection process, since all lightstriking the mask at that area is blocked. However, as the bubble 164approaches the glare line area 150 its surface irregularity or bulgewill pass through a viewing area 163 adjacent the glare area 150 andwill cause rays of light such as the ray 166 to be specularly reflectedas a reflected ray 166' directly into the aperture 162 in the mask 160.This produces a large increase in the light entering the aperture 162and sensed by the photo detector 165, which causes a large variation orspike in the electrical output signal from the inspection sensingdevice.

The arrangement just described has been found effective to sense capsuleimperfections such as bubbles, crimps, turned edges, telescopicallymashed capsules, and the like which cause variations from the circularconfiguration of the capsule surface and hence cause specular reflectionof the intense light into the aperture 162. The photo detectors at thataperture can also sense decreases in diffused light, such as is causedby splits, black spots, holes or cuts occurring in manufacture etc.However, it is preferable not to rely wholly on observation of suchlight-decreases by the detectors 165 which may be set to operate at highlight intensity levels. For more reliable detection of such otherimperfections, and especially splits and cracks at the edge of thecapsule cap 52, the mask 160 is provided with a second aperture 168 anddetector 170 responsive to light from a viewing area 172 positionedoutside the glare area 150, conveniently for example, on the oppositeside of the capsule-lens center line from the glare line area 150. A cutor split passing through that area 172 will cause a variation in thediffusely reflected light reaching the aperture 168, and this willactivate the photo detector 170 located behind that aperture. As shownin FIG. 14, a light ray 169 strikes a cut 171 as it passes through thearea 172 and this will produce variation in the light ray 169' whichenters the aperture 168. The detector 170 is desirably set to respond tolight decreases.

It will be seen that the cut-line observation area is substantially inthe same transverse plane as the glare area 150. This permits both to bein focus for the lens 110. To obtain this result, in the arrangementshown, the angle between the mirror plane 74 and the lens axis isdesirably about 50.

FIG. 15 shows an enlarged image of a capsule as such image appears atthe image plane at the face of the mask 162. The capsule is in invertedposition by reason of the inversion caused by the lens 110. The glareline image appears as a shaded line with its upper capsection displacedto the right of the lower body section. A bulbous enlargement 164 of theglare line image represents the image of the bubble 164. The aperturesof the mask are super imposed on the capsule image. The principalaperture 162 is shown as an open linear area of narrow width having anupper section offset to the right of the lower section so that bothsections lie close to and parallel with the glare line image 150'. Thebulbous image 164' of the bubble 164 is shown to cross the lower sectionof the aperture 162 and represents the passage of light through suchaperture to activate a photo detector 165. FIG. 15 also shows the image171' of the edge split 171 on the cap of the capsule, and shows theaperture 168 in a position to receive light as the image 171' of thesplit passes the aperture 168.

The capsule is of the type in which the cap contains a pair of internalbosses 54 for producing separation resistance of empty capsules, and aseries of internal lands 56 for producing separation resistance infilled capsules. These appear at different levels on the image 125 ofthe capsule as shown in FIG. 15 so that they may be detected by separatephoto detectors placed at corresponding levels.

For detecting defects in the side-scanning system described, a pluralityof detectors 165 a-d are used behind the aperture 162, as shown in FIG.16. Here, an upper detector 165a is disposed at a level to observe lightreflected through the aperture 162 by the indentations or lands 56 andby defects in their vicinity, a second photo detector l65b for detectinglight variations produced by the indentations 54 and by defects in theirvicinity, a detector l65c for detecting defects over the upper portionof the capsule body image, and a detector 165d for detecting defects inthe lower part of the body image. The latter is longer than the othersto take account of normal variations in capsule length. A greater orlesser number of detectors might be used, but we have found four to givegood results. Any of various types of photo detector devices might beused, but we have found it convenient to use edge-contact siliconphotovoltaic cells.

The capsule-end illumination and scanning system is showndiagrammatically in FIGS. 17 and 18. As explained in connection withFIGS. 8-9, the filament 142 lying substantially at the principal focusR1 of the ellipsoidal mirror surface 72 directs rays of light to allpoints on that surface 72 and such rays are reflected toward the capsule25 located substantially at the secondary focus F-2 of the ellipsoidalsurface. That narrow, elongated ellipsoidal surface directs light towardthe capsule 25 over a wide angle in the plane of the capsule so that themirror light source is in eflect wrapped around the ends of the capsule.Thus, in FIG. 8, the bundle of rays c are reflected from near the lowerend of the mirror 72 and thence upward as rays c toward the lower end ofthe capsule 25. This wrap around is especially important in theend-scanning operation, since it produces a glare line area observableby the end scanning lens 1 11 which is of uniquely long length on thecurved end surface of the capsule. Illumination of that sphericalsurface from a spot light source, such as the filament 142 of the lamp70, would produce only a small spot of specularly reflected light asthat end surface is seen by the viewing lens system, and suchillumination provides only limited inspection of the end surface andfails to reveal all the defects. In contrast to this, the illuminationsystem here shown produces a long linear area of specular reflection andgreatly increases the effectiveness of the end inspec- IlOI'l.

In the optical diagram of FIG. 17, a light ray d from the filament I42is reflected from the mirror surface 72 at a at a point 173 well belowits centerline y, and is reflected as a ray d toward the capsule 25 andstrikes the spherical end surface of the capsule at a point D on itsshoulder only a short distance above its line of juncture with thecylindrical side surface of the capsule. The capsule surface reflectsthe ray as a ray d" into the entrance pupil of the end-viewing lens 111of the top end-scanning optical system. Another ray of light e from thefilament 142 is reflected from the mirror surface 72 at a point 174 farabove the centerline y of the mirror and is reflected toward the capsuleas a ray e which strikes such capsule at a point E only a short distancefrom the axis of the capsule. The capsule sur face specularly reflectsthe ray e" into the entrance pupil of the relay lens 111. The points Dand E of incidence of the rays d and e' and of reflection of the rays d"and e" are shown on the large scale FIG. 18 and it is seen that they liefar apart on the arcuate surface of the end of the capsule. The entirelinear area 176 between the points D and E will of course be illuminatedby light rays reflected from points on the mirror surface 72 between thepoints 173 and 174 at which the rays d and e are reflected. Suchillumination will be specularly reflected from the entire linear areabetween the points D and E on the capsule end surface into the lens 111.A glare line is thereby produced on the spherical end of the capsulewhich extends substantially from the line of juncture of the end andside surfaces up to the axis of the capsule. The width of that glareline will be limited in part by the circumferential curvature of the endsurface, but will also be limited by the narrowness of the mirror 72from which the light rays are directed onto the capsule.

By this means, the wrap-around light source formed by the mirror 72produces an elongated linear glare line area on the spherical orsimilarly curved end surface of the capsule as seen by the end-onviewing lens 111. Such lens 111 projects an image of the capsule end onthe face of a mask 178. In that image 225, shown enlarged in FIG. 19,the glare line area appears as a radial linear area 176'. The mask 178is arranged to block the glare light in the glare line area 176' and isprovided with one or more apertures to pass light specularly reflectedfrom the end of the capsule by defects therein. A preferred form of maskaperture 180 is superimposed on the image 225 of the capsule in FIG. 18,and consists of a generally Y-shaped opening in the mask, so positionedthat the radial glare line area 176' lies between the radial arms of theY and generally opposite from the leg of the Y. Y

A single photo detector 182 is positioned behind a mask 178 to detectvariations in the light seen through the aperture 180. The detector maybe made to sense both light increases and decreases, but we have foundit effective to make the detector responsive to light increases. Largelight increases at the aperture 180 will be caused by specularreflection from surface irregularities in a manner analogous to thosecaused by the bubble 164 in the side inspection, as explained inconnection with FIGS. 13 and 14.

It is found that the arrangement described is effective to detectsubstantially all capsule end defects, including not only eccentricsurface deformities but also concentric dimples in the end of thecapsule.

The wrap around lighting system also produces good inspection results oncapsules 200 having parabolic end portions 202 as shown in FIG. 12. Assuch capsules are seen by the side-viewing lens 110, the ellipsoidalmirror produces a glare line area 204 which extends along the cap 206 inthe same manner as on the capsule in FIG. 10, and extends along theparabolic end portion of the body 208 in a continuous curved lineleading well into the shoulder and rounded end of the body. In end-onview, as seen by the end-viewing lens 111, the capsules 200 present anappearance similar to that of the spherical-end capsules as shown inFIG. 11, except that the radial glare line area may be foreshortened atits outer end.

The same apparatus shown may be used to inspect parabolic capsules 200.If desired, however, the sideviewing mask 160 may be replaced by onehaving a principal aperture shaped to extend parallel with the curvedglare line area 250 in the image of the capsule on the face of the mask.

OPERATlON Operation is as follows: Bulk capsules from the hopper aretransferred in uniform cap-down position from the buckets of theconveyor to the inspection head 24 at the LOAD station of that head. Thecapsules 25 are carried in the grooves 28 between the rolls 26 of thehead to the INSPECT station at the left of FIG. 2. Here, each capsule isspun on its axis in a fixed position, located horizontally by thepositions of the supporting rollers 26 and vertically by engagement ofthe end of the cap 56 against the shoulder 48 of such rollers. It isheld in such position by air flow into the suction passage to thesuction chamber 64.

While spinning on its axis in this fixed inspection position, thecapsule 25 is illuminated by the lighting system shown in FIGS. 5-9, 13and 17. All points on the elongated narrow band of ellipsoidal mirrorsurface 72 reflect high intensity light from the filament 142 adjacentthe principal focus F-] of the ellipsoid and direct that light towardthe capsule adjacent the secondary focus F-2 of the ellipsoid. From thepoint of view of the capsule, each point on the surface of the mirrortakes on the brightness of the filament and the capsule sees the mirroras the source of light, in the form of an elongated narrow band in andadjacent the plane of the capsule and extending in that plane through awide arc of approximately l, including on each side of a centerlineperpendicular to the axis of the capsule. This directs high intensitylight onto the capsule in the form of a thin but wide wedge of lightrays which converge toward the capsule over a wide end-to-end angle. Asthe result, the side-scanning lens I10 sees on the capsule a glare lineof specularly reflected light which extends the full length of thecylindrical side surfaces of the capsule body 50 and cap 52 and has endportions which curve into the spherical or otherwise curved closed endsof the body and cap, as shown in FIGS. 10 and 12. The lens 110 producesan image of the illu minated capsule on the surface of the mask at theimage plane, as shown in FIG. 15. The mask blocks specularly reflectedlight in the image of the glare line area I50 but has a narrow aperture162 closely beside that glare line image which passes light specularlyreflected through that aperture from defects such as the bubble 164(FIG. 14) and such light is sensed by one of the photo detectors 16$positioned behind the aperture 162.

The glare line area 150 is sharply-defined by reason of the narrowuniform width of the ellipsoidal mirror 72 from which it is illuminated.

On each end surface of the capsule, the thin, wideangle wedge ofconverging light rays from the ellipsoidal mirror 72 produces a longglare line area 176 which extends from a point close to the base of theend curve to a point close to the axis of the capsule. Specularreflection from that glare line enters the end-viewing lens 111 (or 109)and appears as a generally radial bar 176' on the image 225 of thecapsule end (FIG. 19). The light from that glare line is blocked by themask 178, but light specularly reflected from surface imperfections inthe vicinity of the glare line passes through the Y-shaped aperture 180to be sensed by the photo detector 182. The optical system shown inFIGS. 18 and 19 for the top end of the capsule is duplicated in asimilar system containing the lens 109 for the bottom end of thecapsule.

The light detectors 165, 170, and 182 are connected to controlelectrical circuits having output signals, and so arranged thatvariations in light reaching the detectots produces variations or spikesin the electrical signals. Such signals are processed and analyzed tocontrol the acceptance or rejection of the capsules and to provide otherinformation as desired. A suitable processing apparatus is disclosed inthe aforesaid Chae et al. application.

The optical system for inspection capsules exemplified by the preferredembodiment shown combines illumination and viewing features to produceeffective inspection at high rates of a wide variety of defects inmedicinal capsules, and is effective both with transparent colorlesscapsules and with capsules of various colors and of mixed colors. Theillumination is characterized by the use of means to direct light ontothe capsule in a beam of converging light rays which is thincircumferentially of the capsule but very wide in a plane containing theaxis of the capsule, extending in that plane over a wide angle ofapproximately 80 in each direction from a radial centerline of thecapsule so that the illumination wraps around" the capsule endwise. Suchthin, wide-angled beam of light rays produces, from the point of view ofthe side-scanning lens, a welldefined narrow glare line on the side ofthe capsule which extends the full length of the cylindrical side wallsand into the curved ends of the capsule. It also produces on the ends ofthe capsule a long glare line which extends over a wide arc of thelengthwise curvature of the capsule end, as distinguished from the glarespot produced by a conventional light source which does not wrap aroundthe capsule through the wide angle provided by the present illuminationsystem.

The masks of the optical viewing systems block the light from such glareline areas, and such light is not used in the inspection. However, theproduction of the continuous, elongated, and well defined glare lineareas characterize the illumination which, in the inspection, producesreflections from defects which reveal the presence of those defects witha degree of certainty and reliability not previously available.

In the illustrated embodiment, a single ellipsoidal mirror 72 andillumination system is used to illuminate both the side and the ends ofthe capsule and this is preferred. It is not essential, however, thatthe ends be illuminated by the same lighting mechanism as the side, northat the end-lighting be in the same plane as the side-lighting, sincewith end-on viewing the plane of the end lighting may be freely rotatedabout the axis of the capsule, whereas the plane of side lighting mustbe closely coordinated with the plane of the side-viewing system.

While we consider the single lighting system as shown to be highlyadvantageous and efficient, it will be possible to obtain similar usefulresults with other lighting systems which provide illumination in asimilar configuration and in which the light planes for the ends may bedifferent from the light plane of the side illumination. For example,instead of using a single compact filament 142 and a narrow elongatedmirror surface 72, useful results may be obtained by using an elongatedlight source such as a long-filament lamp or an elongated flurorescentor other radiant tube extending either curved or straight in the desiredplane of illumination. One or both ends of the capsule might beilluminated with the elongated light sources separate from that used toilluminate the side of the capsule. Also, instead of using an elongatedlight source, one might use an elongated series of separate lightsources to produce a somewhat similar result. The accompanying claimsare intended to cover such variations of our invention.

We claim:

1. An optical system for inspecting medicinal capsules or the likehaving longitudinally curved surfaces, while each capsule is spinning onits axis in an inspection position, comprising an optical viewing systemincluding one or more viewing lenses arranged to form at their imageplanes an image representation of an inspection area of the capsulesurface, which area includes both a side surface of the capsule and alongitudinally curved end surface at at least one end of the capsule,

an illumination system including light source means for directing lightrays on to said inspection area for specular reflection therefrom intosaid viewing system, with said light rays emanating from a plurality ofpoints in a light source area which extends endwise of the capsule overa wide are that wraps around at least one end of the capsule, so as toproduce on the capsule as seen by the viewing system a glare line areaof specular reflection which includes both a linear side portion on theside of the capsule and a lineal end portion over an elongated are onthe longitudinally curved end surface of the capsule, and

photo detector means responsive to light in said image representationover one or more areas thereof in spaced relation to the position ofsaid glare line area therein.

2. An optical inspection system as in claim 1 in which the side and endof the capsule is illuminated from a single continuous light source areaextending along side the capsule and around at least one end thereof.

3. An optical inspection system as in claim 2 in which said light sourcearea comprises a reflective surface which lies transverse to a planecontaining the axis of the capsule and extends in said plane through anarc endwise about the capsule, and means to supply light for reflectionfrom said surface on to the capsule.

4. An optical system as in claim 3 in which said reflective surfaceextends in said plane through a substantially elliptical arc having oneof its foci adjacent to the capsule, and a light source adjacent to itsother focus.

5. An optical inspection system as in claim 4 in which said reflectivesurface is substantially in the form of an ellipsoidal surface aboutsaid two foci.

6. An optical inspection system as in claim 5 in which said light sourcemeans is an incandescent filament not centered on said other focus.

7. An optical inspection system as in claim 1 in which said light sourcearea is of substantially uniform width along its length endwise of thecapsule and is narrow circumferentially of the capsule so as to limitthe width of the glare line area produced by specular reflectiontherefrom into said viewing system.

8. An optical inspection system as in claim 5 in which said ellipsoidalreflective surface is a narrow elongated band cut from the ellipsoid atan angle to its axis of revolution.

9. An inspection system as in claim 1 in which said light source meansilluminates said inspection area sub stantially uniformly over itsentire length.

10. An optical inspection system as in claim 1 in which the light raysfrom said inspection area which is thin transversely of the capsule andelongated endwise of the capsule, and in which the rays converge towardthe capsule over a wide angle in the plane of elongation of the beam.

11. An optical inspection system as in claim 1 in which said viewingsystem includes a side-viewing lens arrayed to form an image of aside-surface portion of the capsule, and an end-viewing lens arrayed toform an image of an end-surface portion of the capsule.

12. An optical inspection system as in claim 10 in which said viewingsystem includes a side-viewing lens arrayed to form an image of aside-surface portion of the capsule, and an end-viewing lens arrayed toform an image of an end-surface portion of the capsule.

13. An optical inspection system as in claim 11 in which the end-viewinglens is arranged to view the capsule end-on.

14. An optical inspection system as in claim 13 with the addition of amirror opposite the end of the capsule, the end-viewing lens beingpositioned with its axis at an angle to the capsule axis and viewing thecapsule through said mirror.

15. An optical inspection system as in claim 1 in which said viewingsystem includes a side-viewing lens and two end-viewing lenses, and saidinspection area includes longitudinally curved end surfaces at both endsof the capsule,

said side viewing lens being arrayed so as to form an image of aninspection area extending the full length of the capsule side andincluding an image of the glare line area on the side of the capsulesand each end-viewing lens being arrayed so as to form an image of aninspection area at one end of the capsule which includes an image of thelineal glare area extending over an elongated arc of the curved endsurface of the capsules,

the glare line areas imaged by the three lenses form ing a compositeimage extending substantially the full length of the capsule, wherebythe entire surface of the capsule is inspected simultaneously.

16. An optical inspection system as in claim 1 in which the photodetector means includes at least one detector responsive to light in acapsule end image and at least one detector responsive to light in acapsule side image.

17. An optical inspection system as in claim in which the photo detectormeans includes separate photo detector devices responsive to light inthe separate end and side images respectively.

18. An optical inspection system as in claim 1 in which said inspectionarea includes a substantial portion of the side surface of the capsule,and said photo detector means includes a plurality of detectorsresponsive to light from different portions of said side surface.

19. An optical inspection system as in claim 1 in which said viewingsystem includes a side viewing lens and two end viewing lenses, saidlenses being arrayed to form separate inspection-area images whichtogether form a composite image of an inspection area extendin gsubstantially continuously the full length of the capsule and over itslongitudinally curved ends, and said photo detecting means including aplurality of detectors responsive to light in different portionslengthwise of said composite inspection area image.

20. An optical inspection system as in claim 19 in which said capsuleintermediate its ends includes one or more built-in deviations, therebeing a photo detector separate from the others which is responsive tolight in an inspection area portion in which such deviations appear.

21. An optical inspection system as in claim 1 in which the capsuleincludes one or more built-in deviations which produce a light variationsimilar to that of a defect, there being a separate photo detectorresponsive to light in the inspection area in which such deviationsoccur, the inspection results from said detector being processed todetermine whether additional light variations occur to indicate thepresence of such a defect.

22. Optical inspection apparatus for inspecting medicinal capsules orthe like, comprising means to support and rotate each capsule on itsaxis in an inspection position with its ends exposed axially and itsside exposed laterally for inspection,

a side-viewing lens system having its axis normal to the axis of thecapsule axis,

at least one end viewing lens system having its axis at an angle to thecapsule axis and positioned at the same side of the capsule as saidside-viewing lens system, and a mirror on the axis of the capsule anddisposed to reflect an end-on view thereof into said end-viewing lenssystem.

23. Optical inspection apparatus as in claim 22 which comprises anend-viewing lens system for each end of the capsule, mounted with theiraxes parallel with the axis of the side viewing lens system and in thesame plane therewith, and a mirror on the axis of the capsule at eachend thereof disposed to reflect into the end viewing lens system end-onviews of the two ends of the capsule.

24. Optical inspection apparatus as in claim 23 further comprising anillumination system including a light originating source and areflective surface transverse to a plane at a dihedral angle to theplane of said lens system and extending in said plane through a wide arewhich wraps around the ends of the capsule, said surface being disposedand shaped to reflect light from said source onto said capsule in anarrow elongated beam of converging rays.

25. Optical inspection apparatus as in claim 24 in which said reflectivesurface extends in said plane in an arc of an ellipse having one focusadjacent said light source and the other focus adjacent said capsule.

26. Optical inspection apparatus as in claim 25 in which said reflectivesurface is a strip-shaped section of an ellipsoidal surface.

27. Optical inspection apparatus as in claim 22 in which said dihedralangle is approximately 50, and said side-viewing lens projects an imageof said capsule and of a glare line area thereon, and light sensingmeans at the plane of said image for sensing light in an elongatednarrow area of the capsule image at one side of the glare line areathereon and responsive to specular reflection from capsule surfaceirregularities, and a second light sensing means for sensing lightvariations in an area of the image on the opposite side of the glareline area thereof.

28. Medicinal-capsule inspection apparatus, comprising means forspinning successive capsules on their axis in an inspection position,means for illuminating the capsules by intense light originating at asingle lamp filament and reflected onto the capsule from a mirror in theform of a narrow band cut from an ellipsoid and positioned so that thefilament is adjacent to one focus and the capsule adjacent to the otherfocus, and wherein the mirror wraps around the capsule endwise andproduces on the capsule, as seen by a side-viewing lens and twoend-viewing lenses, a narrow well-defined and continuous glare line areawhich curves over the ends substantially to the axis of the capsule,lenses projecting images of the capsule in side and end elevation on tomasks at the image planes thereof which block the glare light fromacceptable capsules, but contain apertures in spaced relation to theimage glare light areas, which pass light specularly reflected fromdefects in selected observation areas on the spinning capsules, andlight sensors behind the apertures to generate electrical controlsignals which provide inspection output information.

29. An optical system for inspecting medicinal capsules or the likehaving a generally cylindrical side surface, while each capsule isspinning on its axis at an inspection position, comprising,

a side viewing lens system having its axis substantially in a viewingplane containing the axis of the capsule and arranged to form at animage plane an image of the side of the capsule,

an illumination system including light source means for directing lightrays on to the capsule in the direction of a lighting plane containingthe capsule axis and at a dihedral angle to said viewing plane so as toproduce specular reflection into said viewing system from a glare linearea extending lengthwise of the capsule substantially within saiddihedral angle, said glare line area being included in said capsuleimage,

first photo detector means responsive to light in a narrow area of saidcapsule image representing a first viewing area on the capsule at thatside of said glare line area thereon toward said illumination plane,

whereby to sense capsule surface irregularities by specular reflectiontherefrom at angles greater than that from said glare line area.

30. An optical inspection system as in claim 29 further comprisingsecond photo detector means responsive to light in a limited area of thecapsule image representing a second viewing area on the capsule remotefrom the glare line area thereon and on the opposite side of the viewingplane from the glare line area, whereby to sense light reflected fromthe edges of longitudinal splits and the like in said capsule.

31. An optical inspection system as in claim 30 wherein said dihedralangle is approximately 50.

32. An optical inspection system as in claim 30 wherein said first andsecond viewing areas are substantially in the same focal plane of theviewing lens system.

33. An optical inspection system as in claim 29 in which said firstdetector means comprises a plurality of light sensing elementsresponsive respectively to different portions of the light of said glareline area.

34. An optical inspection system as in claim 29 wherein saidillumination system comprises light source means for directing on to thecapsule light rays emanating from a light source area which extendsendwise of the capsule over a substantial distance beyond the ends ofthe capsule so as to converge toward the capsule in the saidillumination plane,

said light source area being of uniform narrow width in the directionnormal to said illuminating plane to delineate the glare line area onthe capsule as a uniform narrow area. 35. An optical inspection systemas in claim 29 wherein said illumination system comprises light sourcemeans for directing on to the capsule light rays emanating from aplurality of points in a light source area which extends endwise of thecapsule over a wide arc in said illumination plane so that such raysconverge on to said capsule from a wide angle in said illuminationplane.

36. An optical system for inspecting medicinal capsules or the likehaving a generally cylindrical side surface, while each capsule isspinning on its axis at an inspection position, comprising aside-viewing lens arranged to form at an image plane an image of theside surface of the capsule,

an illumination system including light source means for directing lightrays on said capsule for specular reflection into said viewing systemfrom a narrow glare line area extending over substantially the wholelength of the capsule side,

and photo detector means responsive to light in said image over anelongated narrow viewing area parallel with and separate from the imageof said glare line area therein,

said detector means including a plurality of light sensing elementsrespectively responsive to light variations at different portions of thelength of said viewing area.

37. An optical inspection system as in claim 36 wherein said lightsource means directs on to the capsule light rays emanating from a lightsource area which extends endwise of the capsule over a wide are so thatsuch rays converge on to the capsule from a wide angle, whereby toimprove observation of surface variations in the vicinity of said glareline area.

38. An optical system for inspecting capsules or like inspectionworkpieces having a spherical or other convex surface of revolution of aconvexly curved line about an axis, while the workpiece is rotated onits axis of revolution, comprising an optical viewing system for viewingthe convex surface from a predetermined direction,

an illumination system including light source means for directing lightrays on to said convex surface for specular reflection therefrom intosaid viewing system,

said rays converging on to said convex surface from a plurality ofpoints in a light source area distributed in a wide are which wrapsaround said convex surface, so as to produce on said surface as seen bysaid viewing system a glare line area of specular reflection extendingover an elongated arc on said convex surface,

said optical viewing system including means for sensing light variationsin a viewing area of the thus-illuminated convex surface as theworkpiece is rotated.

39. An optical inspection system as in claim 38 in which said arcliessubstantially in a plane containing the axis of rotation of theworkpiece.

40. An optical inspection system as in claim 38 in which said viewingsystem views the workpiece in the direction of its axis of revolution.

41. An optical inspection system as in claim 39 in which said viewingsystem views the workpiece in the direction of its axis of revolution.

42. An optical inspection system as in claim 38 in which said lightsource area is of substantially uniform narrow width in the directionnormal to the plane of said arc, so as to limit said glare line area toa narrow linear area.

43. An optical inspection system as in claim 38 in which said lightsource area comprises a reflective sur face extending in an are aboutsaid convex surface, and means to supply light to said reflectivesurface for reflection on to said workpiece.

44. An optical inspection system as in claim 38 further comprising alight originating element, said light source area comprising areflective surface extending in an are about said workpiece surface anddisposed to receive light from said element and reflect the same inconverging rays on to said convex surface.

45. An optical inspection system as in claim 44 in which said reflectivesurface extends in an elliptical arc having one focus adjacent the lightoriginating element and the other focus adjacent the workpiece surface.

46. An optical inspection system as in claim 45 in which said reflectivesurface is a section of an ellipsoid.

47. An optical inspection system as in claim 44 in which said reflectivesurface extends in an arc of a conic section.

48. An optical inspection system as in claim 44 in which said reflectivesurface is a portion of a surface of revolution of a conic section.

49. An optical inspection system as in claim 38 in which said viewingarea is an elongated area beside and separate from said glare line area.

50. An optical inspection system as in claim 39 in which said glare linearea as seen by the axial viewing system is a generally radial area andthe viewing area includes radial areas on both sides of the glare linearea.

51. An optical inspection system as in claim 50 in which the viewingarea includes an area diametrically opposite from said glare line area.

l i i t

1. An optical system for inspecting medicinal capsules or the likehaving longitudinally curved surfaces, while each capsule is spinning onits axis in an inspection position, comprising an optical viewing systemincluding one or more viewing lenses arranged to form at their imageplanes an image representation of an inspection area of the capsulesurface, which area includes both a side surface of the capsule and alongitudinally curved end surface at at least one end of the capsule, anillumination system including light source means for directing lightrays on to said inspection area for specular reflection therefrom intosaid viewing system, with said light rays emanating from a plurality ofpoints in a light source area which extends endwise of the capsule overa wide arc that wraps around at least one end of the capsule, so as toproduce on the capsule as seen by the viewing system a glare line areaof specular reflection which includes both a linear side portion on theside of the capsule and a lineal end portion over an elongated arc onthe longitudinally curved end surface of the capsule, and photo detectormeans responsive to light in said image representation over one or moreareas thereof in spaced relation to the position of said glare line areatherein.
 2. An optical inspection system as in claim 1 in which the sideand end of the capsule is illuminated from a single continuous lightsource area extending along side the capsule and around at least one endthereof.
 3. An optical inspection system as in claim 2 in which saidlight source area comprises a reflective surface which lies transverseto a plane containing the axis of the capsule and extends in said planethrough an arc endwise about the capsule, and means to supply light forreflection from said surface on to the capsule.
 4. An optical system asin claim 3 in which said reflective surface extends in said planethrough a substantially elliptical arc having one of its foci adjacentto the capsule, and a light source adjacent to its other focus.
 5. Anoptical inspection system as in claim 4 in which said reflective surfaceis substantially in the form of an ellipsoidal surface about said twofoci.
 6. An optical inspection system as in claim 5 in which said lightsource means is an incandescent filament not centered on said otherfocus.
 7. An optical inspection system as in claim 1 in which said lightsource area is of substantially uniform width along its length endwiseof the capsule and is narrow circumferentially of the capsule so as tolimit the width of the glare line area produced by specular reflectiontherefrom into said viewing system.
 8. An optical inspection system asin claim 5 in which said ellipsoidal reflective surface is a narrowelongated band cut from the ellipsoid at an angle to its axis ofrevolution.
 9. An inspection system as in claim 1 in which said lightsource means illuminates said inspection area substantially uniformlyover its entire length.
 10. An optical inspection system as in claim 1in which the light rays from said inspection area which is thintransversely of the capsule and elongated endwise of the capsule, and inwhich the rays converge toward the capsule over a wide angle in theplane of elongation of the beam.
 11. An optical inspection system as inclaim 1 in which said viewing system includes a side-viewing lensarrayed to form an image of a side-surface portion of the capsule, andan end-viewing lens arrayed to form an image of an end-surface portionof the capsule.
 12. An optical inspection system as in claim 10 in whichsaid viewing system includes a side-viewing lens arrayed to form animage of a side-surface portion of the capsule, and an end-viewing lensarrayed to form an image of an end-surface portion of the capsule. 13.An optical inspection system as in claim 11 in which the end-viewinglens is arranged to view the capsule end-on.
 14. An optical inspectionsystem as in claim 13 with the addition of a mirror opposite the end ofthe capsule, the end-viewing lens being positioned with its axis at anangle to the capsule axis and viewing the capsule through said mirror.15. An optical inspection system as in claim 1 in which said viewingsystem includes a side-viewing lens and two end-viewing lenses, and saidinspection area includes longitudinally curved end surfaces at both endsof the capsule, said side viewing lens being arrayed so as to form animage of an inspection area extending the full length of the capsuleside and including an image of the glare line area on the side of thecapsules and each end-viewing lens being arrayed so as to form an imageof an inspection area at one end of the capsule which includes an imageof the lineal glare area extending over an elongated arc of the curvedend surface of the capsules, the glare line areas imaged by the threelenses forming a composite image extending substantially the full lengthof the capsule, whereby the entire surface of the capsule is inspectedsimultaneously.
 16. An optical inspection system as in claim 1 in whichthe photo detector means includes at least one detector responsive tolight in a capsule end image and at least one detector responsive tolight in a capsule side image.
 17. An optical inspection system as inclaim 15 in which the photo detector means includes separate photodetector devices responsive to light in the separate end and side imagesrespectively.
 18. An optical inspection system as in claim 1 in whichsaid inspection area includes a substantial portion of the side surfaceof the capsule, and said photo detector means includes a plurality ofdetectors responsive to light from different portions of said sidesurface.
 19. An optical inspection system as in claim 1 in which saidviewing system includes a side viewing lens and two end viewing lenses,said lenses being arrayed to form separate inspection-area images whichtogether form a composite image of an inspection area extendingsubstantially continuously the full length of the capsule and over itslongitudinally curved ends, and said photo detecting means including aplurality of detectors responsive to light in different portionslengthwise of said composite inspection area image.
 20. An opticalinspection system as in claim 19 in which said capsule intermediate itsends includes one or more built-in deviations, there being a photodetector separate from the others which is responsive to light in aninspection area portion in which such deviations appear.
 21. An opticalinspection system as in claim 1 in which the capsule includes one ormore built-in deviations which produce a light variation similar to thatof a defect, there being a separate photo detector responsive to lightin the inspection area in which such deviations occur, the inspectionresults from said detector being processed to determine whetheradditional light variations occur to indicate the presence of such adefect.
 22. Optical inspection apparatus for inspecting medicinalcapsules or the like, comprising means to support and rotate eachcapsule on its axis in an inspection position with its ends exposedaxially and its side exposed laterally for inspection, a side-viewinglens system having its axis normal to the axis of the capsule axis, atleast one end viewing lens system having its axis at an angle to thecapsule axis and positioned at the same side of the capsule as saidside-viewing lens system, and a mirror on the axis of the capsule anddisposed to reflect an end-on view thereof into said end-viewing lenssystem.
 23. Optical inspection apparatus as in claim 22 which comprisesan end-viewing lens system for each end of the capsule, mounted withtheir axes parallel with the axis of the side viewing lens system and inthe same plane therewith, and a mirror on the axis of the capsule ateach end thereof disposed to reflect into the end-viewing lens systemend-on views of the two ends of the capsule.
 24. Optical inspectionapparatus as in claim 23 further comprising an illumination systemincluding a light originating source and a reflective surface transverseto a plane at a dihedral angle to the plane of said lens system andextending in said plane through a wide arc which wraps around the endsof the capsule, said surface being disposed and shaped to reflect lightfrom said source onto said capsule in a narrow elongated beam ofconverging rays.
 25. Optical inspection apparatus as in claim 24 inwhich said reflective surface extends in said plane in an arc of anellipse having one focus adjacent said light source and the other focusadjacent said capsule.
 26. Optical inspection apparatus as in claim 25in which said reflective surface is a strip-shaped section of anellipsoidal surface.
 27. Optical inspection apparatus as in claim 22 inwhich said dihedral angle is approximately 50*, and said side-viewinglens projects an image of said capsule and of a glare line area thereon,and light sensing means at the plane of said image for sensing light inan elongated narrow area of the capsule image at one side of the glareline area thereon and responsive to specular reflection from capsulesurface irregularities, and a second light sensing means for sensinglight variations in an area of the image on the opposite side of theglare line area thereof.
 28. Medicinal-capsule inspection apparatus,comprising means for spinning successive capsules on their axis in aninspection position, means for illuminating the capsules by intenselight originating at a single lamp filament and reflected onto thecapsule from a mirror in the form of a narrow band cut from an ellipsoidand positioned so that the filament is adjacent to one focus and thecapsule adjacent to the other focus, and wherein the mirror wraps aroundthe capsule endwise and produces on the capsule, as seen by aside-viewing lens and two end-viewing lenses, a narrow well-defined andcontinuous glare line area which curves over the ends substantially tothe axis of the capsule, lenses projecting images of the capsule in sideand end elevation on to masks at the image planes thereof which blockthe glare light from acceptable capsules, but contain apertures inspaced relation to the image glare light areas, which pass lightspecularly reflected from defects in selected observation areas on thespinning capsules, and light sensors behind the apertures to generateelectrical control signals which provide inspection output information.29. An optical system for inspecting medicinal capsules or the likehaving a generally cylindrical side surface, while each capsule isspinning on its axis at an inspection position, comprising, a sideviewing lens system having its axis substantially in a viewing planecontaining the axis of the capsule and arranged to form at an imageplane an image of the side of the capsule, an illumination systemincluding light source means for directing light rays on to the capsulein the direction of a lighting plane containing the capsule axis and ata dihedral angle to said viewing plane so as to produce specularreflection into said viewing system from a glare line area extendinglengthwise of the capsule substantially within said dihedral angle, saidglare line area being included in said capsule image, first photodetector means responsive to light in a narrow area of said capsuleimage representing a first viewing area on the capsule at that side ofsaid glare line area thereon toward said illumination plane, whereby tosense capsule surface irregularities by specular reflection therefrom atangles greater than that from said glare line area.
 30. An opticalinspection system as in claim 29 further comprising second photodetector means responsive to light in a limited area of the capsuleimage representing a second viewing area on the capsule remote from theglare line area thereon and on the opposite side of the viewing planefrom the glare line area, whereby to sense light reflected from theedges of longitudinal splits and the like in said capsule.
 31. Anoptical inspection system as in claim 30 wherein said dihedral angle isapproximately 50*.
 32. An optical inspection system as in claim 30wherein said first and second viewing areas are substantially in thesame focal plane of the viewing lens system.
 33. An optical inspectionsystem as in claim 29 in which said first detector means comprises aplurality of light sensing elements responsive respectively to differentportions of the light of said glare line area.
 34. An optical inspectionsystem as in claim 29 wherein said illumination system comprises lightsource means for directing on to the capsule light rays emanating from alight source area which extends endwise of the capsule over asubstantial distance beyond the ends of the capsule so as to convergetoward the capsule in the said illumination plane, said light sourcearea being of uniform narrow width in the direction normal to saidilluminating plane to delineate the glare line area on the capsule as auniform narrow area.
 35. An optical inspection system as in claim 29wherein said illumination system comprises light source means fordirecting on to the capsule light rays emanating from a plurality ofpoints in a light source area which extends endwise of the capsule overa wide arc in said illumination plane so that such rays converge on tosaid capsule from a wide angle in said illumination plane.
 36. Anoptical system for inspecting medicinal capsules or the like having agenerally cylindrical side surface, while each capsule is spinning onits axis at an inspection position, comprising a side-viewing lensarranged to form at an image plane an image of the side surface of thecapsule, an illumination system including light source means fordirecting light rays on said capsule for specular reflection into saidviewing system from a narrow glare line area extending oversubstantially the whole length of the capsule side, and photo detectormeans responsive to light in said image over an elongated narrow viewingarea parallel with and separate from the image of said glare line areatherein, said detector means including a plurality of light sensingelements respectively responsive to light variations at differentportions of the length of said viewing area.
 37. An optical inspectionsystem as in claim 36 wherein said light source means directs on to thecapsule light rays emanating from a light source area which extendsendwise of the capsule over a wide arc so that such rays converge on tothe capsule from a wide angle, whereby to improve observation of surfacevariations in the vicinity of said glare line area.
 38. An opticalsystem for inspecting capsules or like inspection workpieces having aspherical or other convex surface of revolution of a convexly curvedline about an axis, while the workpiece is rotated on its axis ofrevolution, comprising an optical viewing system for viewing the convexsurface from a predetermined direction, an illumination system includinglight source means for directing light rays on to said convex surfacefor specular reflection therefrom into said viewing system, said raysconverging on to said convex surface from a plurality of points in alight source area distributed in a wide arc which wraps around saidconvex surface, so as to produce on said surface as seen by said viewingsystem a glare line area of specular reflection extending over anelongated arc on said convex surface, said optical viewing systemincluding means for sensing light variations in a viewing area of thethus-illuminated convex surface as the workpiece is rotated.
 39. Anoptical inspection system as in claim 38 in which said arc liessubstantially in a plane containing the axis of rotation of theworkpiece.
 40. An optical inspection system as in claim 38 in which saidviewing system views the workpiece in the direction of its axis ofrevolution.
 41. An optical inspection system as in claim 39 in whichsaid viewing system views the workpiece in the direction of its axis ofrevolution.
 42. An optical inspection system as in claim 38 in whichsaid light source area is of substantially uniform narrow width in thedirection normal to the plane of said arc, so as to limit said glareline area to a narrow linear area.
 43. An optical inspection system asin claim 38 in which said light source area comprises a reflectivesurface extending in an arc about said convex surface, and means tosupply light to said reflective surface for reflection on to saidworkpiece.
 44. An optical inspection system as in claim 38 furthercomprising a light originating element, said light source areacomprising a reflective surface extending in an arc about said workpiecesurface and disposed to receive light from said element and reflect thesame in converging rays on to said convex surface.
 45. An opticalinspection system as in claim 44 in which said reflective surfaceextends in an elliptical arc having one focus adjacent the lightoriginating element and the other focus adjacent the workpiece surface.46. An optical inspection system as in claim 45 in which said reflectivesurface is a section of an ellipsoid.
 47. An optical inspection systemas in claim 44 in which said reflective surface extends in an arc of aconic section.
 48. An optical inspection system as in claim 44 in whichsaid reflective surface is a portion of a surface of revolution of aconic section.
 49. An optical inspection system as in claim 38 in whichsaid viewing area is an elongated area beside and separate from saidglare line area.
 50. An optical inspection system as in claim 39 inwhich said glare line area as seen by the axial viewing system is agenerally radial area and the viewing area includes radial areas on bothsides of the glare line area.
 51. An optical inspection system as inclaim 50 in which the viewing area includes an area diametricallyopposite from said glare line area.